The present invention is directed to an apparatus for use with an instrument designed to measure water velocity.
Conventional devices for measuring water velocity generally require a skilled operator to wade into a lake or stream and lower a switch contact closure type water current meter into the water with a wading rod or cable. Because operators must distinguish, via headphones, between spurious noise signals and actual contact closures, there are many opportunities for errors in velocity measurements. Additionally, many of these measuring devices rely upon cumbersome wiring to connect with operator headphones, creating significant potential for operator injury during the measurement process.
The present invention comprises a hand held, battery operated apparatus (a current meter signal processor, or CMSP), for use with a water current velocity measuring device, which provides more reliable measurements than conventional devices. It eliminates the need for a skilled operator and, because it provides for wireless transmission of information, reduces the risk of operator injury from cumbersome wiring. Additionally, the apparatus provides for automatic turn on and shut off.
The CMSP differentiates and amplifies incoming DC signals generated by the current meter into both AC and DC signals, which are then sent to a microprocessor. The microprocessor is equipped with software enabling it to utilize Operations Research (OR) processing. The microprocessor samples and evaluates both the AC and DC signals to determine if a contact closure has occurred (e.g., when the current meter has completed a revolution) and to distinguish an actual contact closure from external voltage discharges or spurious noise pulses.
Upon verification of the occurrence of a contact closure, the microprocessor activates a signal generator and a display block that alert the operator of the contact closure. Additionally, the apparatus provides means for transmitting the information via FM band radio frequency to one or more appropriately tuned FM radios.